Purge Valve Keeps Failing

Post by **br0dy519** » 24 Nov 2021, 22:19

Gentlemen,

I've just replaced my EVAP purge valve for the third time this year. Twice genuine and now I went aftermarket because I wanted to try something different. They all keep failing the same way, solenoid failing to actuate. First one was stuck open then two stuck closed. I tried to "work them" with VIDA and a 12V battery but they just keep dying.

I read online about relays potentially having bad diodes in them and causing transient voltage to be supplied on the contact side. According to the wiring diagram it looks like the purge valve signal is fed directly from the ECM, so not really an "easy" or cheap preventive measure to swap that out.

Anyone have any other bright ideas why these would keep failing? I'm always game for "outside the box" troubleshooting.

Post by **RickHaleParker** » 25 Nov 2021, 01:39

Because you had some stick open and some closed, I would look a source of contamination clogging the valve. Can you open them and manually work the valve? After that cut the valves open and see why they are stuck.

Post by **firstv70volvo** » 25 Nov 2021, 21:15

br0dy519 wrote: ↑24 Nov 2021, 22:19 Gentlemen,

I've just replaced my EVAP purge valve for the third time this year. Twice genuine and now I went aftermarket because I wanted to try something different. They all keep failing the same way, solenoid failing to actuate. First one was stuck open then two stuck closed. I tried to "work them" with VIDA and a 12V battery but they just keep dying.

I read online about relays potentially having bad diodes in them and causing transient voltage to be supplied on the contact side. According to the wiring diagram it looks like the purge valve signal is fed directly from the ECM, so not really an "easy" or cheap preventive measure to swap that out.

Anyone have any other bright ideas why these would keep failing? I'm always game for "outside the box" troubleshooting.

Do you get any codes when the valve fails? I've read (other car models) that the activated charcoal in the EVAP canister can get suck into and cause these purge valves to fail. Not sure what happens that allows the charcoal to get loose in the EVAP line and make its way to the purge valve. As Rick mentioned, might be a good idea to cut open the valve open if it's not obvious there's charcoal clogging things up.

Post by **br0dy519** » 25 Nov 2021, 21:25

Yes I've gotten P0496 and P0497. I did replace what I can only describe as a coupling on the hard plastic line that goes from the purge valve to the rear of the car. It had a 6" length of small ID tubing on it near one of the "raceways" for it. The rubber had expanded and caused a P0442. Perhaps that was introducing some contaminants due to vacuum. I'll hack this one open if it fails again but so far so good, no codes yet after a few days. Maybe if I find carbon I'll add some MERV13 filtration on there

Post by **RickHaleParker** » 25 Nov 2021, 22:05

br0dy519 wrote: ↑25 Nov 2021, 21:25 Maybe if I find carbon I'll add some MERV13 filtration on there

If you find Carbon in the valve that would be a clue that the charcoal canister is breaking down. Might as well fix the problem at the source rather then a band aid fix.

Save the MERV 13 for your cold intake air hack. More surface area, less air flow restriction more power.

Post by **abscate** » 26 Nov 2021, 01:59

Wasn’t there a small filter on the evap line on p80 cars? Maybe that is worth a shot?

Post by **abscate** » 03 Dec 2021, 05:39

abscate wrote: ↑26 Nov 2021, 01:59 Wasn’t there a small filter on the evap line on p80 cars? Maybe that is worth a shot?

9186744

Post by **RickHaleParker** » 03 Dec 2021, 07:07

abscate wrote: ↑03 Dec 2021, 05:39 9186744

For P80 S/V/C70 with emission codes 3 & 4. Some have a Purge Valve filters, some do not.
If the EVAP canister is in the front and square shaped, you have a Purge Valve filter.
If the EVAP canister is in the front and round shaped or located in the back you don't have a Purge Valve filter.

For the P80 S/V/C70: Emission codes 8th digit in the VIN number.
Emission codes 3 & 4 : EVAP canister is in the front, square shaped and you have a Purge Valve filter.
Emission code 0,2,6,B,C,E,F & K : EVAP canister is in the front, round shaped and no Purge Valve filter.
Emission code 7 & 8: EVAP canister is in the rear,, square shaped and no Purge Valve filter.